JPS58110997A - Method of controlling temperature of change-over type heat exchanger group - Google Patents
Method of controlling temperature of change-over type heat exchanger groupInfo
- Publication number
- JPS58110997A JPS58110997A JP56209218A JP20921881A JPS58110997A JP S58110997 A JPS58110997 A JP S58110997A JP 56209218 A JP56209218 A JP 56209218A JP 20921881 A JP20921881 A JP 20921881A JP S58110997 A JPS58110997 A JP S58110997A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- heat exchanger
- gas
- switching
- switching heat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J5/00—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F27/00—Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/40—Air or oxygen enriched air, i.e. generally less than 30mol% of O2
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2280/00—Control of the process or apparatus
- F25J2280/02—Control in general, load changes, different modes ("runs"), measurements
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、切替式熱交換器群の温度制御法に係カ、特に
、空気分離装置に適用され、かつ、少なくとも２１並列
に設置された切替式熱交換器群を安定して運転するのに
好適な切替式熱交換器群の温度制御法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the temperature of a group of switching heat exchangers, and is particularly applicable to an air separation device and a method of controlling the temperature of a group of switching heat exchangers installed in at least 21 parallel heat exchangers. The present invention relates to a temperature control method for a switching heat exchanger group suitable for stable operation.
従来の切替式熱交換器群の温度制御法例をＷＩＪ１図〜
第４図により説明する。Figure WIJ1 shows an example of the temperature control method for a conventional switching heat exchanger group.
This will be explained with reference to FIG.
第１図は、空気分離装置に適用される切替式熱交換器の
構成図で、切替式熱交換器ｌＯは、流路Ａ。FIG. 1 is a block diagram of a switching type heat exchanger applied to an air separation device, and the switching type heat exchanger IO is connected to the flow path A.
Ｂ、Ｃ，Ｄ、Ｅの５流路から連成されている。It is connected to five channels B, C, D, and E.
一定周期ごとに切替えられる流路Ａ、Ｈには、空気分離
装置（図示省略）に送給される原料空気あるいは空気分
離装置から排出される戻シガスが、また、流路Ｃ，Ｄｉ
こは、原料聾気から空気分離装置で分離された製品酸素
と製品窒素が、また、流路Ｅには、再熱ガスがそれぞれ
一定方向に流通する。Flow paths A and H, which are switched at regular intervals, carry raw air fed to the air separation device (not shown) or return gas discharged from the air separation device, and flow paths C and Di
Here, the product oxygen and product nitrogen separated from the raw material air by the air separation device, and the reheated gas flow in the flow path E in a fixed direction.
原料９気は、例えば、流路人を流通する間に流路Ｃ，Ｄ
を流通する製品酸素、製品窒素と熱交換することにより
冷却され、原料空気に含有されていた水分と炭酸ガスは
流路Ａの伝熱面に析出する。For example, the raw material 9 is passed through channels C and D while flowing through channels.
The air is cooled by exchanging heat with the flowing product oxygen and product nitrogen, and the moisture and carbon dioxide contained in the feed air are deposited on the heat transfer surface of the flow path A.
この伝熱面に析出し九本とドライアイスは、次の切替え
で流路Ａを流通する戻シガスによ）昇華し掃気除去され
ろ。The nine particles and dry ice deposited on this heat transfer surface will be sublimated and scavenged by the return gas flowing through channel A in the next switching.
一定周期ごとに切替えられる流路の伝熱面に析出した水
とドライアイスの内、特に、ドライアイスを戻シガスに
よシ効果的に掃気除去するためには、原料空気と戻カガ
スとの温度差を、ドライアイスが昇華により充分掃気除
去できる温度差（以下、掃気温度差と略）以下にする必
要がある。切替式熱交換器では、第２図に実線で示すよ
うに温端部から冷端部に行くに従い原料空気と戻）ガス
の温度差が増加する傾向にあシ、戻ルガスの温度が、１
２５ Ｋ８に以下となる部分から冷端部にかけては、落
２図に一点鎖線で示す掃気温度差以上とな）、ドライア
イスの掃気除去が悪くなる。そのため、流路Ｅに再熱ガ
スを流通させ、纂２図に破線で示すように原料空気と戻
りガスの温度差が掃気温度差以下になるように調整され
ている。なお、再熱ガスには、切替式熱交換器ｌＯで冷
却された原料空気の一部を使用するのが一般的であるが
、その他に、空気分離装置で分離された製品ガス。Of the water and dry ice deposited on the heat transfer surface of the flow path that is switched at regular intervals, in order to effectively scavenge and remove dry ice with the return gas, the temperature of the raw air and the return gas must be adjusted. The difference needs to be less than or equal to the temperature difference (hereinafter abbreviated as scavenging temperature difference) at which dry ice can sufficiently remove scavenging air by sublimation. In a switching heat exchanger, as shown by the solid line in Figure 2, the temperature difference between the feed air and the return gas tends to increase as you go from the hot end to the cold end.
If the scavenging air temperature difference is greater than or equal to the one-dot chain line in Figure 2 from the part below 25 K8 to the cold end, dry ice scavenging removal becomes worse. Therefore, reheated gas is passed through the flow path E and adjusted so that the temperature difference between the raw air and the return gas is equal to or less than the scavenging temperature difference, as shown by the broken line in Figure 2. In addition, although it is common to use a part of the raw material air cooled by the switching type heat exchanger IO as the reheated gas, product gas separated by the air separation device may also be used.
不純窒素ガス、分離する間に発生する他のプロセスガス
が使用されることもある。Impure nitrogen gas and other process gases generated during separation may also be used.
空気分離装置では、このような切替式熱交換器が、第３
図に示すように少なくとも２１並列に設置され適用され
ているが、各切替式熱交換器では、同一仕様で製造した
としても流体抵抗のバラツキは避けられず、また、切替
式熱交換器を連結する止
配管の流体抵抗あるいは配管の灘中に設けられる弁の流
体抵抗等にもバラツキが生じるため流量分配に不平衡が
生じ、その結果、切替式熱交換器各部に温度の不平衡現
象が生じる。このように、切替式熱交換器各部に温度の
不平衡現象が生じると、特定の切替式熱交換器のみが過
冷却され、切替式熱交換器群を安定して運転できなくな
る。したがって、これを防止するには、各切替式熱交換
器各部に温度の不平衡現象が生じないように切替式熱交
換器群の温度を適正に制御する必要がある。In air separation equipment, such a switched heat exchanger
As shown in the figure, at least 21 switching heat exchangers are installed in parallel and applied, but variations in fluid resistance are unavoidable even if each switching heat exchanger is manufactured with the same specifications, and switching heat exchangers are connected in parallel. Variations occur in the fluid resistance of the stop piping or the fluid resistance of the valves installed in the piping, resulting in an unbalance in the flow rate distribution, and as a result, a temperature unbalance phenomenon occurs in each part of the switching heat exchanger. . As described above, when a temperature imbalance phenomenon occurs in each part of the switching heat exchanger, only a specific switching heat exchanger is supercooled, making it impossible to stably operate the switching heat exchanger group. Therefore, in order to prevent this, it is necessary to appropriately control the temperature of the switching heat exchanger group so that a temperature imbalance phenomenon does not occur in each part of each switching heat exchanger.
従来、切替式熱交換器群の温度制御は、次のように打わ
れている。Conventionally, temperature control of a group of switching heat exchangers has been performed as follows.
纂３図で、切替式熱交換１１１０ｉ〜１０ ｃの再熱ガ
ス入口部を除く同一断面での再熱ガスの温度１例えば、
出口温度を切替式熱交換９１０ ｍ−１０ｃの切替弁２
０８〜２）ｃ又は切替弁２１１１〜Ｚｌｃによるそれぞ
れの流路切替え時ごとに温度検出器４０ ａ ” ４１
１１ ｃで検出し、すでに、制御装置刃に記憶されてい
る温度と記憶更新すると同時に、切替式熱交換器群の内
任意の切替式熱交換器、例えば、切替式熱交換９１０
ｍの再熱ガスの出口温度を基準制御温度とし、この基準
制御温度に他の切替式熱交換器１０ｂ。In Figure 3, the temperature 1 of the reheat gas at the same cross section except for the reheat gas inlet of the switchable heat exchangers 1110i to 1110c, for example,
Switching outlet temperature heat exchanger 910m-10c switching valve 2
08~2) Temperature detector 40 a '' 41 each time the flow path is switched by c or switching valves 2111 to Zlc.
11c and updates the memory with the temperature already stored in the control device blade, and at the same time, any switching heat exchanger in the switching heat exchanger group, for example, the switching heat exchanger 910
The outlet temperature of the reheated gas of m is set as a reference control temperature, and the other switching type heat exchanger 10b is set at this reference control temperature.
１０ ｃの再熱ガスの出口温度が一致するように切替式
熱交換器１０ｂ、１０ｃの再熱ガスの流量を流量制御弁
Ｚｉｂ、２２ｃの弁開度を制御装置Ｉ３Ｄによル調節し
、例えば、基準制御温度よシも他の切替式熱交換器１０
ｂ、ｌｏｃの再熱ガスの出口温度が高い場合には、他の
切替式熱交換１１１０ｂ、１０ｃの再熱ガスの流通量が
増量するように、逆に低い場合には、減量するように調
整される。The flow rates of the reheated gases in the switching heat exchangers 10b and 10c are adjusted by the control device I3D, and the valve openings of the flow rate control valves Zib and 22c are adjusted so that the outlet temperatures of the reheated gases in the reheated gases 10c and 10c are the same, for example. , standard control temperature and other switching heat exchangers 10
When the outlet temperature of the reheat gas of b and loc is high, the flow rate of the reheat gas of the other switching heat exchangers 1110b and 10c is adjusted to increase, and when it is low, the flow rate is adjusted to decrease. be done.
このような切替式熱交換器群の温度制御法では、切替式
熱交換器群の再熱ガスの出口温度を平衡に調整で鳶るが
、しかし、次のような欠点があった。In this method of controlling the temperature of the switching heat exchanger group, the outlet temperature of the reheated gas of the switching heat exchanger group can be balanced and adjusted, but it has the following drawbacks.
（１） 切替式熱交換器での原料空気の出口温度と戻
シガスの入口温度との温度差に無関係に、切替式熱交換
器の再熱ガス入口部を除く同一断面での再熱ガスの温度
のみで熱交換器群の温度を平衡にバランスさせているた
め、ドライアイスが戻シガスによシ未だ効果的に掃気除
去されない。(1) Regardless of the temperature difference between the outlet temperature of the feed air and the inlet temperature of the reheated gas in the switching heat exchanger, Since the temperature of the heat exchanger group is balanced by temperature alone, dry ice is not yet effectively scavenged and removed by the return gas.
つま夛、切替式熱交換器の冷端部での原料空気と戻ヤガ
スとの温度差が大きい場合は、第４図に実線で示す熱交
換器冷端部の同一断面での原料空気と戻シガスとの温度
差が、第４図に一点鎖線で示す掃気温度差以上となシ、
ドライアイル０掃気除去が悪くな夛、その結果、切替式
熱交換器群を安定して運転できなくなる。逆に、切換式
熱交換器の冷端部での原料空気と戻）ガスとの温度差が
小さい場合は、原料空気の流通量が戻シガスと製品酸素
と製品窒素の総和流通量に対して少量の時であシ、切替
式熱交換器置端部を流通する原料空気と、戻シガス、製
品酸素、製品窒素との温度差が大きくなり、冷熱の回収
が悪くなると共に、切替式熱交換器の中間部の同一断面
での原料空気と戻カガスとの温度差が大きくなシ、第４
図の破線で示すように掃気温度差以上になる部分があシ
、この場合も、ドライアイスが効果的に掃気除去されな
くなシ、その結果、切替式熱交換器群を安定して運転で
きなくなる。If the temperature difference between the raw air and the return gas at the cold end of the switching type heat exchanger is large, the temperature difference between the raw air and the return gas at the same cross section of the cold end of the heat exchanger, as shown by the solid line in Figure 4, is large. If the temperature difference between the scavenging air and the scavenging gas is greater than or equal to the scavenging air temperature difference shown by the dashed line in Figure 4,
If dry aisle zero scavenging air removal is poor, the switching heat exchanger group cannot be operated stably as a result. Conversely, if the temperature difference between the feed air and the return gas at the cold end of the switching heat exchanger is small, the flow rate of the feed air will be greater than the total flow rate of the return gas, product oxygen, and product nitrogen. When a small amount is used, the temperature difference between the raw air flowing through the end of the switching heat exchanger and the return gas, product oxygen, and product nitrogen becomes large, and the recovery of cold heat becomes poor, and the switching heat exchanger If there is a large temperature difference between the raw air and the return gas at the same cross section in the middle of the vessel, the fourth
As shown by the broken line in the figure, there are areas where the temperature difference is higher than the scavenging air temperature difference, and in this case as well, dry ice cannot be effectively removed by the scavenging air, and as a result, the switching heat exchanger group cannot be operated stably. It disappears.
本発明は、上記欠点の解消を目的としたもので、切替式
熱交換器群の内で温度制御の基準となる切替式熱交換器
を設定し、蚊切替式熱交換器では、切替式熱交換器での
原料空気の出口温度と戻りガスの入口温度との温度差が
掃気温度差を満足するように定めた切替式熱交換器での
再熱ガスの出口温度を基準制御温度として、該基準制御
温度と検出された基準となる切替式熱交換器での再熱ガ
スの出口温度とを比較し、諌再熱ガスの出口温度が前記
基準制御温度に一致するように基準となる切替式熱交換
器での再熱ガスの流通量を調整し、かつ、他の切替式熱
交換器では、基準となる切替式熱交換器での検出された
再熱ガスの出口温度を制御目標温度として、該制御目標
温度と他の切替式熱交換器での検出され几再熱ガスの出
口温度とを比較し、該再熱ガスの出口温度が前記制御目
標温度に一致するように他の切替式熱交換器での再熱ガ
スの流通量を調整すると共に、前記基準制御温度を検出
された原料空気の出口温度と戻シガスの入口温度との温
度！！により変更することを特徴とし、切替式熱交換器
群の温度を平衡にバランスさせると共に、一定周期ごと
に切替えられる流路の伝熱面に析出したドライアイスを
効果的に掃気除去し切替式熱交換器群を安定して運転で
きる切替式熱交換器群の温度制御法を提供するものであ
る。The present invention aims to eliminate the above-mentioned drawbacks, and sets a switching heat exchanger as a standard for temperature control among a group of switching heat exchangers. The outlet temperature of the reheated gas in the switching heat exchanger is determined so that the temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas in the exchanger satisfies the scavenging temperature difference. The standard control temperature is compared with the detected outlet temperature of the reheated gas in the standard switching type heat exchanger, and the standard switching type is adjusted so that the outlet temperature of the reheated gas matches the standard switching type heat exchanger. The flow rate of reheat gas in the heat exchanger is adjusted, and in other switching heat exchangers, the outlet temperature of the reheat gas detected in the reference switching heat exchanger is used as the control target temperature. , the control target temperature is compared with the detected outlet temperature of the reheated gas in the other switching type heat exchanger, and the other switching type heat exchanger is set so that the outlet temperature of the reheated gas matches the control target temperature. While adjusting the flow rate of reheat gas in the heat exchanger, the reference control temperature is determined to be the temperature between the detected raw material air outlet temperature and the returned gas inlet temperature! ! The switchable heat exchanger balances the temperature of the switchable heat exchanger group and effectively scavenges and removes dry ice deposited on the heat transfer surface of the flow path that is switched at regular intervals. The present invention provides a temperature control method for a switchable heat exchanger group that allows stable operation of the exchanger group.
本発明の一実施例を第５図、第６図によシ説明するＯ
第５図は、本発明を実施した切替式熱交換器群のフロー
シートで、切替式熱交換器１０ ａ〜１０ ｃの再熱ガ
スの出口温度は、切替式熱交換器１０ｍ〜１０Ｃそれぞ
れの流路切替え時ごとに温度検出器４０ａ〜４０ｃによ
）検出され、また、原料空気の出口温度と戻シガスの入
口温度は数回の流路切替えに１回の割合いで温度検出器
４１ ａ 〜４１ Ｃ＃ ４２ ｍ −４２ｃによ〕検
出され、これら検出された温度は、既に制御装置美に記
憶されている温度と記憶更新される。次に各切替式熱交
換器の温度制御は次のように行われる。An embodiment of the present invention will be explained with reference to FIGS. 5 and 6. FIG. 5 is a flow sheet of a group of switchable heat exchangers in which the present invention is implemented. The outlet temperature of the reheated gas in c is detected by the temperature detectors 40a to 40c each time the flow paths of the switchable heat exchangers 10m to 10C are switched, and the outlet temperature of the raw air and the inlet of the reheated gas are detected. The temperature is detected by the temperature detectors 41a to 41C# 42m-42c once every several flow path changes, and these detected temperatures are the temperatures already stored in the control device. The memory is updated. Next, temperature control of each switching type heat exchanger is performed as follows.
まず、切替式熱交換器１０ ａ〜１０ ｃの内、温度制
御の基準となる切替式熱交換器（以下、基準熱交換器と
略）を設定する。基準熱交換器を例えば切替式熱交換器
群鳳と設定すれば、切替式熱交換器１０ Ｍでは、検出
され制御装置園に記憶更新された再熱ガスの出口温度と
、原料空気の出口温度と戻ｐガスの入口温度との温度差
が掃気温度声を満足するように任意に定めた再熱ガスの
出口温度（以下、基準制御温度と略）との比較を制御装
置Ｉで行い、検出された再熱ガスの温度が基準制御温度
に一致するよ）に、制御装置Ｉ３ｏで流量調節弁２２ａ
の弁開度を調節し再熱ガスの流通量を調整する。First, among the switching heat exchangers 10 a to 10 c, a switching heat exchanger (hereinafter abbreviated as a reference heat exchanger) is set as a reference for temperature control. If the reference heat exchanger is set as a switching heat exchanger, for example, the switching heat exchanger 10M will have the outlet temperature of the reheated gas and the outlet temperature of the raw air, which have been detected and stored and updated in the controller. The control device I compares the temperature difference between the temperature difference between the temperature difference between the temperature difference between the temperature at the inlet temperature of the reheated gas and the outlet temperature of the reheated gas (hereinafter referred to as the reference control temperature), which is arbitrarily determined so that the temperature difference between the temperature at the inlet of the returned p-gas satisfies the scavenging temperature, The controller I3o controls the flow rate control valve 22a so that the temperature of the reheated gas matches the reference control temperature.
The flow rate of reheat gas is adjusted by adjusting the opening degree of the valve.
例えば、検出された再熱ガスの鉦度が基準制御温度よシ
も高い場合には、再熱ガスの流通量を増量させ、逆に、
低い場合には、減量させる。これと同時に、他の切替式
熱交換１１１０ｂ、１０ｃでは、切替式熱交換器１０
ｍの検出された再熱ガスの出口温度を制御目標温度とし
て、他の切替式熱交換器１０ｂ、１０ｃの検出され制御
装置薗に記憶更新された再熱ガスの出口温度と制御目標
温度との比較を制御装［３０で行い、検出された他の切
替式熱交換器１０ｂ、１０ｃの再熱ガスの出口温度が制
御目標温度に一致するように、制御装置園で流量調節弁
２２ｂ。For example, if the detected temperature of the reheated gas is higher than the standard control temperature, the flow rate of the reheated gas is increased, and conversely,
If low, reduce dose. At the same time, in the other switchable heat exchangers 1110b and 10c, the switchable heat exchanger 10
Using the detected outlet temperature of the reheated gas of m as the control target temperature, the detected and updated reheated gas outlet temperatures of the other switching heat exchangers 10b and 10c and the control target temperature are set. A comparison is made in the controller 30, and the controller controls the flow control valve 22b so that the detected outlet temperature of the reheated gas of the other switching heat exchangers 10b, 10c matches the control target temperature.
２２ｃの弁開度を調節し再熱ガスの流通量を調整する。The flow rate of the reheated gas is adjusted by adjusting the opening degree of the valve 22c.
例えば、検出された他の切替式熱交換器１０ ｂの再熱
ガスの出口温度が制御目標温度よりも高い場合には、他
の切替式熱交換器１０ ｂの再熱ガスの流通量を増量さ
せ、逆に、低い場合には、減量させる。このようにして
切替式熱交換器群の再熱ガスの出口温度は平衡に制御さ
れるが、しかし、切替式熱交裸畔評の原料９気の出口温
度は流体抵抗のバラツキのため同一温度でなく、場合に
よりては、原料空気の出口温度と戻シガスの入口温度と
の温度差が切替式熱交換器の冷端部での原料空気な
と戻りガスとの温度差が掃気温度差を越えるよう。For example, if the detected outlet temperature of the reheat gas of the other switching heat exchanger 10 b is higher than the control target temperature, the flow rate of the reheat gas of the other switching heat exchanger 10 b is increased. Conversely, if it is low, reduce the amount. In this way, the outlet temperature of the reheated gas in the switchable heat exchanger group is controlled in equilibrium.However, the outlet temperature of the raw material 9 in the switchable heat exchanger is kept at the same temperature due to variations in fluid resistance. In some cases, the temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas may cause the temperature difference between the feed air and the return gas at the cold end of the switching heat exchanger to cause the scavenge temperature difference. Let's overcome it.
原料空気の川口温度と戻りガスの入口温度との温度差を
上限とし、また、切替式熱交換器の中間部での原料９気
と戻シガスとの温度差が掃気温度差を越えるような原料
９気の出口温度と戻ルガスの入口温度との温度差を下限
とする原料９気の出口温度と戻ルガスの入口温度との温
度差の許容値（以下、許容値と略）を外れることがある
。The upper limit is the temperature difference between the inlet temperature of the feed air and the inlet temperature of the return gas, and the temperature difference between the feed air and the return gas at the middle part of the switching heat exchanger exceeds the scavenging temperature difference. The temperature difference between the exit temperature of the raw material 9 and the inlet temperature of the return gas, whose lower limit is the temperature difference between the outlet temperature of the 9 gas and the inlet temperature of the return gas, may not exceed the allowable value (hereinafter abbreviated as the tolerance value). be.
そこで、検出された切替式熱交換器１０ ａ〜１０ ｃ
での原料空気の出口ｉｉ＊と戻りガスの入口温度との温
度差が許容値内にある場合は、不感帯として現状の基準
制御温度は変更しないが、しかし、次のような場合は、
感帯として現状の基準制御温度を変更する。Therefore, the detected switching heat exchangers 10a to 10c
If the temperature difference between the raw air outlet ii* and the return gas inlet temperature is within the allowable value, the current standard control temperature will not be changed as a dead zone. However, in the following cases,
Change the current standard control temperature as a sensitive zone.
（１）検出された原料空気の出口温度と戻シガスの入口
温度との温度差が許容値を外れる切替式熱交換器が少な
くとも１基ある場合
まず、検出された原料空気の出口温度と戻シガスの入口
温度との温度差が許容値の上限を越えた場合、つまシ、
第４図の実線で示すように切替式熱交換器の冷端部での
検出された原料空気と戻シガスとの温度差が掃気温度差
以上となった場合は、ドライアイスを効果的１こ掃気除
去するためには、第６図のように、再熱ガスの流通量を
大として再熱ガスの出口温度を低くし、これによシ原料
叩気の出口温度な俳下させ切替式熱交換器の冷端部での
検出された原料空気と戻シガスとの温度差が掃気温度差
以下となるようにする必要がある。そのため、この場合
には、現状の基準制御温度を低い値に変更する。(1) If there is at least one switching heat exchanger in which the temperature difference between the detected outlet temperature of the raw air and the inlet temperature of the returned gas is outside the allowable value. If the temperature difference from the inlet temperature exceeds the upper limit of the allowable value, the
As shown by the solid line in Figure 4, if the temperature difference between the raw air and the returned gas detected at the cold end of the switching heat exchanger exceeds the scavenging temperature difference, dry ice is effectively removed once. In order to remove the scavenging air, as shown in Figure 6, the flow rate of the reheated gas is increased to lower the outlet temperature of the reheated gas, and this lowers the outlet temperature of the raw material beating air. It is necessary to ensure that the detected temperature difference between the raw air and the returned gas at the cold end of the exchanger is equal to or less than the scavenging temperature difference. Therefore, in this case, the current reference control temperature is changed to a lower value.
ｔｙｃ、検出された原料空気の出口温度と戻シガスの入
口温度との温度差が許容値の下限を下まわった場合、つ
まり、第４図の破線で示すように切替式熱交換器の中間
部での原料空気と戻シガスとの温度差が掃気温度差以下
となった場合は、ドライアイスを効果的に掃気除去する
ためには、再熱ガスの流通量を小として再島ガスの出口
温度を高くし、切替式熱交換器の中間部での原料９気と
戻多ガスとの温度差が掃気温度差以下となるようにする
必要があル、そのため、この場合には、現状の基準制御
温度を高い値に変更する。tyc, when the detected temperature difference between the outlet temperature of the raw air and the inlet temperature of the return gas is below the lower limit of the allowable value, that is, as shown by the broken line in Figure 4, the middle part of the switching heat exchanger If the temperature difference between the raw air and the returned gas is less than the scavenging temperature difference, in order to effectively scavenge and remove dry ice, the flow rate of the reheated gas should be kept small and the outlet temperature of the reheated gas should be lowered. It is necessary to make the temperature difference between the raw material gas and the return gas at the middle part of the switching heat exchanger higher than the scavenging temperature difference. Change the control temperature to a higher value.
（２）検出された原料空気の出口温度と戻ルガスの入口
温度との温度差が許容値の上限を越える切替式熱交換器
と、許容値の下限を下１わる切替式熱交換器とが同時に
存在する場合
この場合は、許容値の上限を越える切替式熱交換器の温
度制御を優先して、上記と同様に行い、その後、許容値
の下限を下まわる切替式熱交換器の温度制御を上記と同
様に行う。(2) A switchable heat exchanger in which the detected temperature difference between the outlet temperature of the feed air and the return gas inlet temperature exceeds the upper limit of the allowable value, and a switchable heat exchanger in which the detected temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas exceeds the lower limit of the allowable value. If they exist at the same time, in this case, prioritize the temperature control of the switching heat exchanger that exceeds the upper limit of the allowable value and perform the same as above, and then control the temperature of the switchable heat exchanger that falls below the lower limit of the allowable value. Do the same as above.
本実施例の切替式熱交換器の温度制御法では、切替式熱
交換器群での再熱ガスの出口温度をバランスさせること
ができると共に、この状態で、切替式熱交換器群各部で
の原料９気と戻）ガスとの温＆！！を掃気温度差以下に
常に制御で龜一定周期ごとに切替えられる流路の伝熱面
に析出したドライアイスを効果的に掃気除去できる。In the temperature control method of the switching heat exchanger according to this embodiment, it is possible to balance the outlet temperature of the reheated gas in the switching heat exchanger group, and in this state, the temperature control at each part of the switching heat exchanger group can be balanced. Raw materials 9 qi and return ) temperature with gas &! ! Dry ice deposited on the heat transfer surface of the flow path can be effectively removed by controlling the scavenging temperature difference to always be below the scavenging temperature difference, which is switched at regular intervals.
なお、本実施例では、切替式熱交換器を３１並列に設置
した例につき説明したが、特に、これに限定するもので
はなく、切替式熱交換器が少なくとも２１並列に設置さ
れていれば、適用上特に問題はない。In this example, an example in which 31 switching heat exchangers are installed in parallel has been described, but the invention is not limited to this, and as long as at least 21 switching heat exchangers are installed in parallel, There are no particular problems in application.
本発明は、以上説明したように、切替式熱交換器群の内
で温度制御の基準となる切替式熱交換器を設定し、該切
替式熱交換器では、切替式熱交換器での原料空気の出口
温度と戻シガスの入口温度との温度差が掃気温度差を満
足するように定めた切替式熱交換器での再熱ガスの出口
温度を基準制御温度として、該基準制御温度と検出され
た基準となる切替式熱交換器での再熱ガスの出口温度と
を比較し、該再熱ガスの出口温度が前記基準制御温度に
一致するように基準となる切替式熱交換器での再熱ガス
の流通量を調整し、かつ、他の切替式熱交換器では、ｔ
ＩＬ記基準基準る切替式熱交換器での検出された再熱ガ
スの出口温度を制御目標温度として、鋏制御目標温度と
他の切替式熱交換器での検出された再熱ガスの出口温度
とを比較し、腋再熱ガスの出口温度が前記制御目標温度
に一致するように他の切替式熱交換器での再熱ガスの流
通量を調整すると共に、前記基準制御温度を検出された
原料空気の出口温度と戻シガスの入口温度との温度差に
よ）変更するということで、切替式熱交換器群の温度を
平衡にバランスさせろことができると共に、この状態で
、一定周期ごとに切替えられる流路の伝熱面に析出した
ドライアイスを効果的に掃気除去できるので、切替式熱
交換器群を安定して運転できる効果がある。As explained above, the present invention sets a switching heat exchanger that serves as a reference for temperature control among a switching heat exchanger group, and in the switching heat exchanger, the raw material in the switching heat exchanger is The outlet temperature of the reheated gas in the switching heat exchanger is determined so that the temperature difference between the air outlet temperature and the return gas inlet temperature satisfies the scavenging temperature difference, and is detected as the reference control temperature. The outlet temperature of the reheated gas in the reference switching heat exchanger is compared with the outlet temperature of the reheated gas in the reference switching heat exchanger, and the temperature in the reference switching heat exchanger is adjusted so that the outlet temperature of the reheated gas matches the reference control temperature. Adjust the flow rate of reheat gas, and in other switching type heat exchangers, t
The control target temperature is the detected outlet temperature of the reheated gas in the switching heat exchanger based on the IL standard, and the scissor control target temperature and the detected outlet temperature of the reheated gas in the other switching heat exchangers. The flow rate of the reheat gas in the other switching heat exchangers is adjusted so that the outlet temperature of the armpit reheat gas matches the control target temperature, and the reference control temperature is detected. By changing the temperature (based on the difference between the outlet temperature of the feed air and the inlet temperature of the return gas), it is possible to balance the temperature of the switchable heat exchanger group, and in this state, the temperature of the switchable heat exchanger group can be balanced at regular intervals. Since the dry ice deposited on the heat transfer surface of the switched flow path can be effectively scavenged and removed, the switchable heat exchanger group can be operated stably.
第１図から第４図は、従来の切替式熱交換器群の温度制
御法例を説明するもので、第１図は、切替式熱交換器の
構成図、第２図は、切替式熱交換器の各部の戻シガスの
温度と、原料空気と戻りガスとの温度差および掃気温度
差との関係線図、第３図は、従来の温度制御法を実施し
た切替式熱交換器群のフローシート、第４図は、原料空
気の出口温度と戻シガスの入口温度との温度差が異なる
場合の、切替式熱交換器の各部の戻ｐガスの温度と、原
料９気と戻シガスとの温度差との関係線図、第５図、第
６図は、本発明の一実施例を説明するもので、第５図は
、本発明の温度制御法を実施した切替式熱交換器群のフ
ローシート、ｊ１！６図は、原料空気流通量に対する再
熱ガス流通量の比と再熱ガスの出口温度および切替式熱
交換器の冷端部並びに中間部での原料９気と戻りガスと
の温度差との関係線図である。
１０．１０ｍから１０ ｃ・・・・・・切替式熱交換器
、２２ｍから２２ｃ・・・・・・流量制御弁、Ｉ・・・
・・・制御装置、４０ｍから４０ｃ、４１ｍから４１ｃ
、４２ｍから４２ ｃ ＝温度検出器
才１ｔＺ１
才２１２Ｉ
ｆ３グ
ｊ【ソだ人
′ｔ′４Ｉ２１
才５図Figures 1 to 4 illustrate examples of temperature control methods for conventional switching heat exchanger groups. Figure 1 is a configuration diagram of a switching heat exchanger, and Figure 2 is a switching heat exchanger group. Figure 3 is a diagram showing the relationship between the temperature of the return gas in each part of the vessel, the temperature difference between the feed air and the return gas, and the temperature difference of the scavenging air. Figure 4 shows the temperature of the return p-gas in each part of the switching heat exchanger and the difference between the raw material air and the return gas when the temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas is different. The relationship diagrams with temperature difference, FIGS. 5 and 6, explain one embodiment of the present invention. FIG. 5 shows a group of switching heat exchangers implementing the temperature control method of the present invention. Flow sheet, Figure J1!6 shows the ratio of the flow rate of reheated gas to the flow rate of raw material air, the outlet temperature of reheated gas, and the relationship between raw material 9 air and return gas at the cold end and intermediate part of the switching heat exchanger. It is a relationship diagram with the temperature difference of . 10.10m to 10c...switching heat exchanger, 22m to 22c...flow control valve, I...
...control device, 40m to 40c, 41m to 41c
, 42m to 42c = Temperature detector 1tZ1 212I f3guj
Claims (1)
れぞれ流通する流路な有し、前記原料空気と前記戻）ガ
スとの流路が周期的に切替えられる切替式熱交換器が、
少なくとも２基並列に設置された切替式熱交換器群の温
度制御法において、前記切替式熱交換器群の内で温度制
御の洩 基準となる切替式熱交ｚ器を設置し、鋏切替式熱交換器
では、切替式熱交換器での前記原料空気の出口温度と前
記戻シガスの入口温度との温度差が、原料空気が流通す
る前記流路に析出したドライアイスを戻りガスにより効
果的に掃気除去できる原料空気と戻シガスとの掃気温度
差を満足するように定めた切替式熱交換器での前記再熱
ガスの出口温度を基準制御温度として、腋基準制御温度
と検出された基準となる切替式熱交換器での再熱ガスの
出口温度とを比較し、腋再熱ガスＯ出口温度が前記基準
制御温度に一致するように基準となる切替式熱交換器で
の再熱ガスの流通量を調整し、かつ、他の切替式熱交換
器では、前記基準となる切替式熱交換器での検出された
再熱ガスの出口温度を制御目標温度として、蚊制御目標
温度と他の切替式熱交換器での検出された再熱ガスの出
口温度とを比較し、該再熱ガスの出口温度が前記制御目
標温度に一致するように他の切替式熱交換器での再熱ガ
スの流通量を調整すると共に、前記基準温度を、検出さ
れた原料空気の出口温度と戻〕ガスの入口温度との温度
差にょシ変更することを特像とする切替式熱交換器群の
温度制御法。 ２、前記切替式熱交換器群の内、検出された原料空気の
出口温度と戻シガスの入口温度との温度差が、切替式熱
交換器の冷端部での前記原料空気と前記戻）ガスとの温
度差が、前記掃気温度差以上となる原料空気の出口温度
と戻シガスの入口温度との温度差の上限を越える切替式
熱交換器が少なくとも１基存在する場合は、前記基準制
御温度を低い値に変更し、切替式熱交換器の中間部での
原料空気と戻りガスとの温度差が、掃気温度差以上とな
る原料空気の出口温度と戻シガスの入口温度との温度差
の下限を下まわる切替式熱交換器が少なくとも１基存在
する場合は、基準制御温度を高い値に変更し、また、同
時に存在する場合は、検出された原料空気の出口温度と
戻夛ガスの入口温度との温度差が前記上限を越える切替
式熱交換器を優先して、基準制御温度を低い値に変更し
、その後、基準制御温度を高い値に変更する特許請求の
範１！ｌ＠１項記載の切替式熱交換器群の温度制御法。 ３、 前記基準制御温度に比較し検出された前記基準と
なる切替式熱交換器での前記再熱ガスの出口温度が高い
場合には、基準となる切替式熱交換器での再熱ガスの流
通量を増量させ、逆に、低い場合には、減量させると共
に、前記制御目標温度に比較し検出された前記他の切替
式熱交換器での再熱ガスの出口温度が高い場合には、他
の切替式熱交換器での再熱ガスの流通量を増量させ、逆
に、低い場合には、減量させる特許請求の範囲第１項記
載の切替式熱交換器群の温度制御法。[Claims] 1. A switchable type having a flow path through which feed air, return gas, separated gas, and reheated gas flow, and in which the flow paths for the feed air and return gas are periodically switched. The heat exchanger is
In a temperature control method for a switchable heat exchanger group in which at least two units are installed in parallel, a switchable heat exchanger that serves as a leakage reference for temperature control is installed in the switchable heat exchanger group, and a scissors switchable In the heat exchanger, the temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas in the switching heat exchanger allows the dry ice deposited in the flow path through which the feed air flows to be more effectively removed by the return gas. The outlet temperature of the reheated gas in the switching heat exchanger, which is determined to satisfy the scavenging temperature difference between the feed air and the return gas that can be scavenged and removed, is set as the reference control temperature, and the armpit reference control temperature and the detected reference Compare the outlet temperature of the reheated gas in the switching type heat exchanger to be used as the standard, and adjust the reheated gas in the standard switching type heat exchanger so that the axillary reheated gas O outlet temperature matches the reference control temperature. At the same time, in other switching heat exchangers, the outlet temperature of the reheated gas detected in the reference switching heat exchanger is used as the control target temperature, and the mosquito control target temperature and other switching heat exchangers are adjusted. The detected outlet temperature of the reheated gas in the switching heat exchanger is compared, and the reheating is performed in the other switching heat exchanger so that the outlet temperature of the reheated gas matches the control target temperature. A switchable heat exchanger group characterized by adjusting the flow rate of gas and changing the reference temperature according to the temperature difference between the detected raw material air outlet temperature and the return gas inlet temperature. Temperature control method. 2. Among the switching heat exchanger group, the temperature difference between the detected outlet temperature of the raw air and the inlet temperature of the return gas is such that the temperature difference between the detected raw material air and the return gas at the cold end of the switching heat exchanger is If there is at least one switching heat exchanger whose temperature difference with the gas exceeds the upper limit of the temperature difference between the outlet temperature of the raw material air and the inlet temperature of the return scavenging gas, which is equal to or higher than the scavenging temperature difference, the reference control is performed. Change the temperature to a lower value so that the temperature difference between the feed air and return gas at the intermediate part of the switching heat exchanger is greater than or equal to the scavenging temperature difference.The temperature difference between the outlet temperature of the feed air and the inlet temperature of the return gas. If there is at least one switchable heat exchanger whose temperature is below the lower limit, change the standard control temperature to a higher value, and if they exist at the same time, change the detected raw air outlet temperature and return gas temperature. Claim 1: Prioritizing the switching heat exchanger whose temperature difference from the inlet temperature exceeds the upper limit, the reference control temperature is changed to a lower value, and then the reference control temperature is changed to a higher value! 1@ Temperature control method for a group of switching heat exchangers described in Section 1. 3. If the detected outlet temperature of the reheated gas in the reference switching heat exchanger is higher than the reference control temperature, the temperature of the reheated gas in the reference switching heat exchanger is higher. The flow rate is increased, and conversely, when it is low, it is decreased, and when the detected outlet temperature of the reheat gas in the other switching heat exchanger is higher than the control target temperature, A temperature control method for a group of switching heat exchangers according to claim 1, in which the flow rate of reheat gas in other switching heat exchangers is increased, and conversely, when it is low, the flow rate is decreased.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56209218A JPS6019439B2 (en) | 1981-12-25 | 1981-12-25 | Temperature control method for switching heat exchanger group |
| US06/451,960 US4459143A (en) | 1981-12-25 | 1982-12-21 | Temperature control method for reversing type heat exchanger group of air separation system |
| DE19823247838 DE3247838A1 (en) | 1981-12-25 | 1982-12-23 | TEMPERATURE CONTROL METHOD FOR A GROUP OF SWITCHABLE HEAT EXCHANGERS OF AN AIR SEPARATOR |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56209218A JPS6019439B2 (en) | 1981-12-25 | 1981-12-25 | Temperature control method for switching heat exchanger group |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58110997A true JPS58110997A (en) | 1983-07-01 |
| JPS6019439B2 JPS6019439B2 (en) | 1985-05-16 |
Family
ID=16569299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56209218A Expired JPS6019439B2 (en) | 1981-12-25 | 1981-12-25 | Temperature control method for switching heat exchanger group |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4459143A (en) |
| JP (1) | JPS6019439B2 (en) |
| DE (1) | DE3247838A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3706529A1 (en) * | 1987-02-28 | 1988-09-08 | Linde Ag | Process and apparatus for evaporating a liquefied gas |
| FR2684089B1 (en) * | 1991-11-26 | 1994-01-14 | Air Liquide | PROCESS FOR THE COMBINED AND ADJUSTABLE FLOW PRODUCTION OF NITROGEN AND OXYGEN. |
| JP3002218U (en) * | 1994-03-18 | 1994-09-20 | 株式会社イソワ | Ink supply / collection mechanism for corrugated board printing machine |
| GB9607792D0 (en) * | 1996-04-15 | 1996-06-19 | Boc Group Plc | Air separation apparatus |
| FR2789162B1 (en) * | 1999-02-01 | 2001-11-09 | Air Liquide | PROCESS FOR SEPARATING AIR BY CRYOGENIC DISTILLATION |
| JP5416284B2 (en) * | 2010-10-21 | 2014-02-12 | キョンドン ワン コーポレーション | Control method for parallel operation of multiple water heaters |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2617275A (en) * | 1948-01-06 | 1952-11-11 | Kellogg M W Co | Separation of gaseous mixtures |
| DE1284432B (en) * | 1965-06-10 | 1968-12-05 | Linde Ag | Process for the removal of easily condensable components from gas mixtures to be broken down at low temperature in periodically switchable heat exchangers |
| DE1751383A1 (en) * | 1968-05-20 | 1971-02-18 | Linde Ag | Method and device for heat exchange in the low-temperature decomposition of gas mixtures |
| GB1478419A (en) * | 1975-01-28 | 1977-06-29 | Air Prod & Chem | Reversible heat exchanger or regenerator systems |
| JPS51111950A (en) * | 1975-03-28 | 1976-10-02 | Kobe Steel Ltd | Temperature control method of a change-over type heat exchanger for ai r separator |
-
1981
- 1981-12-25 JP JP56209218A patent/JPS6019439B2/en not_active Expired
-
1982
- 1982-12-21 US US06/451,960 patent/US4459143A/en not_active Expired - Fee Related
- 1982-12-23 DE DE19823247838 patent/DE3247838A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| US4459143A (en) | 1984-07-10 |
| DE3247838A1 (en) | 1983-07-14 |
| DE3247838C2 (en) | 1988-03-17 |
| JPS6019439B2 (en) | 1985-05-16 |
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